Hinges are arranged in orthopedic devices and guide or assist articulation of a joint, such as a knee joint. Some hinges are robust, including multiple parts and structural elements, and facilitate and guide movement of a joint. Such robust hinges may not be necessary in applications of lighter-weight orthopedic devices in that their functional and structural features may be excessive. Such robust hinges may add to weight, cost, bulk, resistance to joint movement, and complexity of an orthopedic device. When such aspects are unwarranted, they are to the disadvantage of a user.
As an alternative to the robust hinges, some lighter-weight orthopedic devices include a lightweight hinge, such as a stay, upright, or flexible bar permitting articulation of the orthopedic device. These hinges permit articulation in a manner that reinforces the orthopedic device upon bending but are less intended for facilitating movement of joint. The lightweight hinges may be embedded or securely enclosed within a panel such as a tubular sleeve in the orthopedic device, and do not engage or couple to other structural features in the orthopedic device, aside from the tubular sleeve.
While these hinges offer joint guidance and support, and retain at least in part the shape of the orthopedic device when defined as a flexible tubular sleeve, they are not adaptable to different characteristics including rigidity, strength, and range or motion control, particularly according to different activity levels. These lightweight hinges may be limited in their use as defining elongate members that have no other function or features aside from opening as a hinge or a stay. There is a problem of lightweight hinges not providing sufficient control or guidance of motion in one or more directions. Additionally, there is a problem of existing lightweight hinges not adapting to the dynamic shape of a user's lib, especially between flexion and extension, while still providing needed strength and effectively cooperating with other elements of an orthopedic device, such as a compressive sleeve.